Investigators will be taking a look at his criminal past and whether he has a history of mental illness, the chief said at the news conference, held at the site of the stabbing in the 1400 block of 11th Street Northwest in the Logan Circle neighborhood of D.C.

“I live in this city. I think that it is unsettling for anyone who lives in this city to see something like this happen. This is a very isolated incident. We don’t see crimes very much like this, even during the course of my career,” Newsham said. “This is an extremely safe neighborhood. This is a very unusual incident.”

The suspect was caught on video after the attack on Tuesday just before 8 p.m. He was wearing a distinctive mustard color shirt, which he was not wearing at the time of his arrest Wednesday night in a Columbia Heights park, Newsham said.

The knife was also recovered from the scene.

Martinez, 35, was out for a jog, and sought help in a nearby takeout restaurant after the stabbing. Her family described her as an avid runner.

“A woman jogging on our street is a normal activity. ... This is a woman who should be going to work today,” Bowser said.

There’s no indication the attacker knew Martinez. The stabbing was “unprovoked,” Newsham said, and the motive remains unclear.

“The entire FiscalNote family is shocked and deeply saddened to learn that Wendy Martinez, our Chief of Staff, was killed last night,” CEO Tim Hwang said in a statement Wednesday. “Wendy was an invaluable member of our team and a vibrant member of the community. Our thoughts and prayers are with Wendy’s family and friends.”

FiscalNote finalized the acquisition of CQ Roll Call from The Economist Group on Aug. 20.